Electrical transmission of moving pictures



[April 10, 1934. w. E. JOHN ELECTRICAL TRANSMISSION OF MOVING PICTURES Filed Sept. 16, 1930 Q/IVVENTOR WE EY fmvsrrfiH/v 57-4 7, [4%

HTTORNCIS Patented Apr. 10, 1934 UNITED STATES ELECTRICAL TRAN SllIIS SIGN OF MOVING PICTURES Wesley Ernest John, Merton Park, London, England Application September 16, 1930, Serial No. 482,231 In Great Britain October 12, 1929 3 Claims. (Cl. 1786) This invention refers to the transmission of moving pictures by television methods in which the transmitted image is subdivided into units which are transmitted successively.

In transmitting a still picture the transmitting apparatus works under the favourable condition of scanning an object which can be uniformly illuminated and occupies a single focal plane. This condition is not present when a natural scene is presented to the transmitting 1g apparatus but can be attained if a kinematograph film of the natural scene is made and projected onto a screen, the image on the screen being then scanned by the transmitter.

The usual intermittently projected film image,

however, introduces the difficulty that any lack of synchronism between the scanning periodicity and the periodicity of the exposure of the moving picture produces a phenomenon equivalent to beats between musical notes of slightly different pitch, which manifests itself as flickering of the transmitted picture.

This difliculty is overcome according to the present invention by presenting to the scanning means at the transmitting station, a film image 23 which is continuously projected.

The invention is illustrated in the accompanying diagrammatic drawing.

2 indicates a screen onto which the film image is projected. The television transmitting device,

33 comprising a scanning disc 3 and a light-sensitive cell 4 energized by the light transmitted by said disc, is arranged to scan the picture appearing on said screen 2.

The moving picture is projected onto the screen 33 by apparatus, indicated generally by 5, of the known type which projects continuously. In the apparatus shown the film 6 and a series of lenses 7 move continuously and parallel with one another, and a fixed lens 8 optically compensates for the movement. A suitable apparatus of this kind is described in the specification of Patent No. 1,768,772.

The film 6 is preferably photographed by means of a camera which operates similarly to the projector, so that there is no interruption of the exposure of the film. In this way all the movement of the original scene is recorded on the film and appears on the screen 2; and the continuity of movement in the resulting teletransmitted picture is correspondingly improved.

I claim:

1. The process which consists in forming a screen image by projecting onto a screen a stationary image of a continuously moving picture film bearing pictures which records motion uninterruptedly and so that said image is uninterruptedly present on the screen, and transmitting the image by television apparatus including a normal scanning device for scanning stationary objects.

2. The process of transmitting pictures which consists in projecting light uninterruptedly through a continuously moving motion picture film onto a screen, and causing the light to be reflected onto an optical system forming an element of a transmission circuit.

3. The process of transmitting pictures which consists in projecting light uninterruptedly through a continuously moving lens system and through a continuously moving motion picture film onto a screen, and causing the light to be reflected onto an optical system forming an element of a transmission circuit.

WESLEY ERNEST JOHN. 

